Electrical measuring instrument



Dec. 18 1928. 1,695,861

- A. R. RUTT'ER ET AL ELECTRI CAL MEASURING INSTRUMENT Filed Aug. 29, 1927 INVENTORS WaH-er- G Mylius and Argyl e Russell RU'H'er.

ATTbRNEY Patented Dec. 1 8, 1928.

UNITED STA PATENT OFFICE.

AltG-YLE n. BUTTER, 0E FOREST H1LLS,'AND WALTER G. MYLIUS, 0E wILKINsEuEe, PENNSYLVANIA, ASSIGNOR-S To .WESTINGI-IOUSE ELECTRIC AND MANUFACTUR- ING corirANY, A GORPORATIQN OF PENNSYLVANIA.

ELECTRICAL MEASURING INSTRUMENT.

Application filed August 29, 1927. Serial No. 216,292.

Our invention relates to electrical measur ing instruments and particularly to lightloadradjusting devices for such instruments.

Our invention resides in apparatus for minutely adjusting the light-load compensating device of an induction motor'meter, and it is characteristic ofour apparatus that it furnishes an extremely accuratev and delicate adjustment forthe angula-rly displaced cooperating fluxes utilizable for overcoming the friction and bearing load that is present in all induction motor meters. I

It is further characteristic'ot our invention that we provide highly etlective and convenient means for retaining the lightdoad adjustment mechanism in fixed position after adjustment.

In a watthour meter of the usual type, a

core is provided with a plurality otspaced pole pieces for receiving, respectively, winding's adapted to be energized in accordance with the values of current and voltage existing in the circuit with which the meter is associated. A disc armature is disposed between the pole pieces in such manner that rotationof the disc is effected in accordance with thc 'flux set up by said windings.

In accordancewitli our invention, we provide a plurality of closed-circuit members that are pivotally mounted on the core 1nem ber of a watthour meter in aposition to at- .fect the rotation of the armature of the meter by the interaction of the voltage flux with tluX generated in the closed-circuit members by the voltage flux. Means are provided, further, whereby movement of the closed- .circuit members, to vary upon the armature, may small increments.

Our inventioln resides in the apparatus hereinafter described and claimed, the foregoing and further characteristics of our invention being determinable from the following description.

For an understanding of a form our apparatus may take reference is to be had to the accompanying. drawings, in which Figure 1 is a view in elevation of a-portion of an electrical measuring instrument embodying our invention, V

Fig. 2 is a View, partially plan and partial- 1y cross sectional, of a portion of the instrube effected in very mentshown in Fig. 1, taken along the line 11-11, and Fig. 3 is a view similar to Fig. 2 taken on the line'111.-111 of Fig. 1.

An electrical measuring instrument 1 comprises-a magnetizable core member 2 and an "armature 3 that is adapted to'rotate a shaft 4 in accordance with the magnitude of an electrical quantity, such as the power traversing' an electrical circuit comprising the conductors 5 and 6. To thisend, there coacts with the armature 3 the fluxes induced in one or more current windings 7 and a vol age winding 7. connected, respectivcly, in

seriescircuitfrelation and across the aforesaid circuit comprising the conductors 5 and 6. The latter constitute a suitable electrical circuit that is adapted to transmit, an electrical quantity from a source of electrical energy, such as an alternating current generator G to a receiver of such electrical en ergy, such as an alternating current motor M. The armature 3 drlves an indicating or in? tegrating device (not shown) in the usual well known manner to record the total amount of power traversing the conductors 5 and 6 The usual permanent magnet for damplng the disc 3 is provided, but has been omitted from the' drawing to more clearly illustrate the primary feature of our invention. 3 p

In order that the friction, particularly at light loads, between relatively movable parts of the instrument may not cause inaccurateregistration of the amount of energy traversing the conductors 5 and (lduring a specific interval of time, we provide a compensating means which comprisesv a plurality of closed coils .8 and 8 consisting, preferably of a sinproper dimensions and suitable gle loop of material, preferably non-magconducting netic in character, as tions 9 of the aforesaid coils 8 and 8 are movable, respectively, in air gaps 10 disposed between. the projections 11 and the pole piece 12 ofthe core member 2. The coils 8 and 8' are each pivotally supported at 13; the for H161 is provided with a locking set screw 14 while the lattcris provided with speed reducing mechanism, as hereinafter described.

. The flux produced by the coil 7 cuts the brass or the like. Porloops 8, 8 and. induces currents therein feet of friction may be largely or entirely.

overcome and the arn'iature 3 caused to rotate at substantially constant speed, at light load as Well as at heavier loads.

in accordance with our inventi n, suitable mechanismis utilized "for adju ig one of the aforesaid loops 8 or 8 by v small increments. As one example of such mechanism, there is provided a gear wheel 15, preferably accessible from the exterior of the meter casing and suitably mountedon the core member 2 to cooperatively gear segmentloformed on member comprised in the loop 8. Gear wheel is provided with (a slotted portion 17, which when e1 r ged .with a suitable tool, such as a screw driver, changes the position of the loop 8 with respect to the air gap 10.

As stated above the conductino' member 8 is pivoted at 13 and this connection comprises a tap bolt 18 that is rotatably disposed in a suitable hole provided in the core member 2. One end ofmember 8 is disposed between the shouldered end of bolt 18 and a plate and the other end thereof is mounted between nuts 19. Said one end of member 8 comprises a polygonal flange portion coacting with a similarly shaped bolt head 20 of the bolt 18. W hen it is desired to adjust the member 8, the set screw 14- is loosenedand the bolt head 20 is turned to move the loop 8 in the proper direction, an arcuate slot 26 permitting rotational movement of the member 8Q The loop 8 is locked in-position after adjustment by tightening the set screw 1%.

As stated above, the loop 8 is pivoted at 1,3 and, in theexample illustrated, this connection comprises a pair of pivot screws 21 threaded into opposite faces of the core memher 2. One of the aforesaid pivot screws 21 is provided with a head, between which and a space plate 25, one end of the loop 8 is disposed. The other pivot screw 21 has secured thereto a plurality of nuts 22 between which the other end of loop 8 is mounted. By preference, the gear wheel 15 comprises a shaft 24 suitably retained in a passage extending through the magnetizahle structure 2.

To offset adjustment of the loop, 8, the lower screw 21 of Fig. 8, may be slightly'retracted whereupon the gear 15 may be rotated by application of a screw driver or similar tool to the slot 17. Due to the gear mec 'ianism illustrated, relatively great movementof gear 15' results only in relatively slight movement of loop 8. Hence, the relation of said loop 8 with respect to the core 2 may be adjusted with precision and nicety, thereby regulating the speed characteristics of armature 8 in a similar manner. Thereafter, the lower screw '21, of Fig. 3, may be tightened to positively retain loopS in the position to which moved.

It shall be understood that, in lieu of the' gear mechanism herein described for effecting movement of the loop 8, there may be utilized generally equivalent arrangements. Thus, for example, the member in which the loop 8 terminates may be provided with a gear segment with which a worm is adapted to mesh, the worm functioning similarly to the herein disclosed gear wheel 15. We claim as our inventlonz 1. In an alternating-current-m'otor meter,

the combination with a magnetizable core having a central member and a side member separated therefrom by an air gap, of a closed-circuit conductor comprising a portion movable in said air gap, an extension integral with said conductor and constituting a gear rack, and a pinion operatively engaging said gear rack.

2. The combination withv a magnetizablecore having members separated by an'air gap, of a closed-circuit conductor comprising aportion movable in said air gap, means for moving said conductor with respect to said core comprising a gear segment carried by said conductor and a pinion mount-ed upon said core and operatively engaging said seg ment, and means for retaining said conductor in an adjusted position. 7 a

In testimony whereof, we'have hereunto subscribed our names this 24th day of August, 1927.

ARGYLE n. nurrnn. WALTER o. MYLi s. 

